This invention relates to semiconductor device power modules, and more specifically relates to a novel power module employing insulated gate bipolar transistors ("IGBT") with self-contained driver and control circuits.
Power module semiconductor devices are well known and are generally multiple die packages for high power applications such as uninterruptible power supplies, motor drive controls, switching power supplies and high frequency welders. Such power modules will typically contain two or more semiconductor device die which may be diodes, thyristors, MOSFETs or Darlington-connected transistor die or combinations of such a die which are connected in predetermined circuit relationships such as half-wave bridges, full-wave bridges, parallel connections and the like. The die are usually thermally coupled to but are electrically isolated from a massive heat sink. The module then contains an insulation housing for enclosing the die and their connections. Terminal connections for a.c. or d.c. terminals and for control terminals are made available at the surface of the housing.
A typical power module is disclosed in International Rectifier Data Sheet No. PD-9.453B which illustrates a half-bridge configuration consisting of two power MOSFETs contained within a common housing and connected in good thermal relationship to a massive heat sink. This Data Sheet appears in the "HEXFET Power MOSFET Designer's Manual" published by International Rectifier Corporation, 4th Edition, dated 9/87, pages F-39 through F-44. The internal construction of such devices is illustrated typically in U.S. Pat. No. 4,047,197.
Power modules now require external driver circuits, external isolators to isolate control circuitry from the power devices within the housing and appropriate control circuits designed for the power modules such as current-limiting and current-tripping circuits which respond to a fault or other current condition sensed in the output current. Thus, considerable external circuitry has to be designed or provided by the user of the module.
It has also been desirable to use IGBT die in place of, for example, bipolar Darlington transistor die in power modules particularly for motor drive applications. However, standard IGBTs generally have only a few microseconds short-circuit capability whereas motor-drive applications require at least 10 to 20 microseconds short-circuit capability.
IGBT characteristics can be modified for higher short-circuit ability but only at the expense of other important device characteristics.